Add support for asynchronous search providers

Some search providers may want to change their results, or may not
want to block on an external service to get their results (DBus, etc.)
Set up an infrastructure to allow search providers to add their search
results at a later time.

Based on a patch by Jasper St. Pierre and Seif Lotfy.

https://bugzilla.gnome.org/show_bug.cgi?id=655220

js/ui/search.js

@@ -112,6 +112,43 @@ function SearchProvider(title) {
 SearchProvider.prototype = {
     _init: function(title) {
         this.title = title;
+        this.searchSystem = null;
+        this.searchAsync  = false;
+    },
+
+    _asyncCancelled: function() {
+    },
+
+    startAsync: function() {
+        this.searchAsync = true;
+    },
+
+    tryCancelAsync: function() {
+        if (!this.searchAsync)
+            return;
+        this._asyncCancelled();
+        this.searchAsync = false;
+    },
+
+    /**
+     * addItems:
+     * @items: an array of result identifier strings representing
+     * items which match the last given search terms.
+     *
+     * This should be used for something that requires a bit more
+     * logic; it's designed to be an asyncronous way to add a result
+     * to the current search.
+     */
+    addItems: function(items) {
+        if (!this.searchSystem)
+            throw new Error('Search provider not registered');
+
+        if (!items.length)
+            return;
+
+        this.tryCancelAsync();
+
+        this.searchSystem.addProviderItems(this, items);
     },
 
     /**
@@ -315,6 +352,7 @@ SearchSystem.prototype = {
     },
 
     registerProvider: function (provider) {
+        provider.searchSystem = this;
         this._providers.push(provider);
     },
 
@@ -331,12 +369,23 @@ SearchSystem.prototype = {
         this._previousResults = [];
     },
 
+    addProviderItems: function(provider, items) {
+        this.emit('search-updated', provider, items);
+    },
+
     updateSearch: function(searchString) {
         searchString = searchString.replace(/^\s+/g, '').replace(/\s+$/g, '');
         if (searchString == '')
-            return [];
+            return;
 
         let terms = searchString.split(/\s+/);
+        this.updateSearchResults(terms);
+    },
+
+    updateSearchResults: function(terms) {
+        if (!terms)
+            return;
+
         let isSubSearch = terms.length == this._previousTerms.length;
         if (isSubSearch) {
             for (let i = 0; i < terms.length; i++) {
@@ -349,11 +398,11 @@ SearchSystem.prototype = {
 
         let results = [];
         if (isSubSearch) {
-            for (let i = 0; i < this._previousResults.length; i++) {
+            for (let i = 0; i < this._providers.length; i++) {
                 let [provider, previousResults] = this._previousResults[i];
+                provider.tryCancelAsync();
                 try {
                     let providerResults = provider.getSubsearchResultSet(previousResults, terms);
-                    if (providerResults.length > 0)
                     results.push([provider, providerResults]);
                 } catch (error) {
                     global.log ('A ' + error.name + ' has occured in ' + provider.title + ': ' + error.message);
@@ -362,9 +411,9 @@ SearchSystem.prototype = {
         } else {
             for (let i = 0; i < this._providers.length; i++) {
                 let provider = this._providers[i];
+                provider.tryCancelAsync();
                 try {
                     let providerResults = provider.getInitialResultSet(terms);
-                    if (providerResults.length > 0)
                     results.push([provider, providerResults]);
                 } catch (error) {
                     global.log ('A ' + error.name + ' has occured in ' + provider.title + ': ' + error.message);
@@ -374,8 +423,7 @@ SearchSystem.prototype = {
 
         this._previousTerms = terms;
         this._previousResults = results;
-
+        this.emit('search-completed', results);
-        return results;
+    },
-    }
 };
 Signals.addSignalMethods(SearchSystem.prototype);

js/ui/searchDisplay.js

@@ -189,6 +189,8 @@ function SearchResults(searchSystem, openSearchSystem) {
 SearchResults.prototype = {
     _init: function(searchSystem, openSearchSystem) {
         this._searchSystem = searchSystem;
+        this._searchSystem.connect('search-updated', Lang.bind(this, this._updateCurrentResults));
+        this._searchSystem.connect('search-completed', Lang.bind(this, this._updateResults));
         this._openSearchSystem = openSearchSystem;
 
         this.actor = new St.BoxLayout({ name: 'searchResults',
@@ -223,9 +225,11 @@ SearchResults.prototype = {
         this._selectedProvider = -1;
         this._providers = this._searchSystem.getProviders();
         this._providerMeta = [];
-        for (let i = 0; i < this._providers.length; i++)
+        this._providerMetaResults = {};
+        for (let i = 0; i < this._providers.length; i++) {
             this.createProviderMeta(this._providers[i]);
-
+            this._providerMetaResults[this.providers[i].title] = [];
+        }
         this._searchProvidersBox = new St.BoxLayout({ style_class: 'search-providers-box' });
         this.actor.add(this._searchProvidersBox);
 
@@ -305,6 +309,12 @@ SearchResults.prototype = {
         }
     },
 
+    _clearDisplayForProvider: function(index) {
+        let meta = this._providerMeta[index];
+        meta.resultDisplay.clear();
+        meta.actor.hide();
+    },
+
     reset: function() {
         this._searchSystem.reset();
         this._statusText.hide();
@@ -319,15 +329,24 @@ SearchResults.prototype = {
         this._statusText.show();
     },
 
+    doSearch: function (searchString) {
+        this._searchSystem.updateSearch(searchString);
+    },
+
     _metaForProvider: function(provider) {
         return this._providerMeta[this._providers.indexOf(provider)];
     },
 
-    updateSearch: function (searchString) {
+    _updateCurrentResults: function(searchSystem, provider, results) {
-        let results = this._searchSystem.updateSearch(searchString);
+        let terms = searchSystem.getTerms();
-
+        let meta = this._metaForProvider(provider);
-        this._clearDisplay();
+        meta.resultDisplay.clear();
+        meta.actor.show();
+        meta.resultDisplay.renderResults(results, terms);
+        return true;
+    },
 
+    _updateResults: function(searchSystem, results) {
         if (results.length == 0) {
             this._statusText.set_text(_("No matching results."));
             this._statusText.show();
@@ -337,7 +356,7 @@ SearchResults.prototype = {
             this._statusText.hide();
         }
 
-        let terms = this._searchSystem.getTerms();
+        let terms = searchSystem.getTerms();
         this._openSearchSystem.setSearchTerms(terms);
 
         // To avoid CSS transitions causing flickering
@@ -349,10 +368,16 @@ SearchResults.prototype = {
 
         for (let i = 0; i < results.length; i++) {
             let [provider, providerResults] = results[i];
+            if (providerResults.length == 0) {
+                this._clearDisplayForProvider(i);
+            } else {
+                this._providerMetaResults[provider.title] = providerResults;
+                this._clearDisplayForProvider(i);
                 let meta = this._metaForProvider(provider);
                 meta.actor.show();
                 meta.resultDisplay.renderResults(providerResults, terms);
             }
+        }
 
         if (this._selectedOpenSearchButton == -1)
             this.selectDown(false);

js/ui/viewSelector.js

@@ -297,7 +297,7 @@ SearchTab.prototype = {
     _doSearch: function () {
         this._searchTimeoutId = 0;
         let text = this._text.get_text().replace(/^\s+/g, '').replace(/\s+$/g, '');
-        this._searchResults.updateSearch(text);
+        this._searchResults.doSearch(text);
 
         return false;
     }